More details, please. Which platform are you installing to? Are you using an automated installer, i.e. the BWS? What exactly do you mean with "automatically choosing French", does it say so in the install window or do you see it by the texts inside the game?

In the normal install routine, it is impossible for the mod to automatically chose a language of its own. Maybe you try to install to BG:EE and French is game language the installer wants to install to? In this case, delete the weidu.conf file in your BG:EE folder and try to install the mod again.

If this is not your problem, please also post teh content of the "Setup-gavin.DEBUG" here.